The present invention generally relates to a transfer assembly and, more particularly, to a low impact transfer assembly which can be used to transfer articles from one conveyor to another conveyor.
Transfer conveyors for transferring articles or sorting articles from a conveyor onto take-away conveyors are well known in the art. Typically, the transfer assembly includes a pusher arm which moves across the conveyor to an extended position to push an article from the conveyor to the take-away conveyor which is often angled with respect to the first conveyor. These pusher arms have taken many forms and, until recently, have not achieved high transfer rates while maintaining the impact on the article to a minimum. One recent diverter which has successfully achieved high sortation rates while maintaining a low impact on the article is disclosed in pending U.S. patent application Ser. No. 08/933,818, entitled xe2x80x9cLOW IMPACT ARTICLE DIVERTER ASSEMBLY,xe2x80x9d now U.S. Pat. No. 6,068,105, which is commonly assigned to Mannesmann Dematic of Grand Rapids, Mich., the disclosure of which is herein incorporated by reference in its entirety. Rather than blocking the forward motion of the article, the low impact diverter of the Mannesmann diverter assembly transforms the forward motion of the article into a lateral motion across the conveyor onto the take-away conveyor.
In some applications, it may be desirable to move an article between two generally parallel conveyors. For example, when articles are conveyed on a conveyor through an x-ray machine and it is determined that an article requires manual inspection, the conveyor passing through the x-ray machine is stopped so that the article can be inspected while remaining on the conveyor. Thus, the flow of passengers through the x-ray area is often impeded when an article requires manual inspection. In order to minimize the impact on the flow of the articles through the x-ray machine, some operators remove the article from the conveyor and place the article on a table where it is manually inspected. However, this requires manual lifting by the operator and, further, requires the operator to be distracted from the operation of the x-ray again slowing the flow of passengers through the x-ray area.
Consequently, there is a need for a transfer assembly which can transfer an article from a first conveyor to a second adjacent and generally parallel conveyor for diverting the article to the second conveyor while maintaining the flow of the first conveyor generally constant. In addition, there is need for a transfer device which can achieve this transfer at a relatively fast sortation rate to avoid creating any impedance to the flow on the first conveyor while providing a low impact to the article being transferred so that any fragile or breakable objects contained in the article will not be damaged during the transfer.
Accordingly, a transfer assembly of the present invention provides for a low impact transfer of an article from a first conveyor to a second diverting conveyor, so that articles can be diverted from the first conveyor to the second diverting conveyor without impeding the flow of the first conveyor. This transfer is done at a relatively fast rate while maintaining the impact on the article at a minimum.
In one form of the invention, a transfer assembly for transferring articles between two conveyor sections, which are offset laterally from one another, includes a conveying surface and a pusher. The pusher is adapted to move across a first portion of the conveying surface, from a retracted position adjacent the first portion, to an extended position across the first portion adjacent a second portion of the conveying surface for translating an article being conveyed on the conveying surface and for transferring the article from the first conveyor section to the second conveyor section.
In one aspect, the pusher initially moves across the first portion at a first speed to contact the article and then moves the article across the first portion a second speed, wherein the first speed is less than the second speed thereby generating a low impact with the article. In further aspects, the pusher straddles the conveying surface. For example, the transfer assembly may include a frame, with the frame supporting the conveying surface, and the pusher being movably supported by the frame. In one form, the pusher is movably supported by the frame by a pair of rails.
In further aspects, the pusher includes downwardly depending portions which straddle the conveying surface, with the downwardly depending portions being interconnected by a transverse member and being movably supported by the transverse member on the frame. The transverse member may be moved laterally across the frame, for example, by a rotating arm. The rotating arm preferably includes a wheel which engages the transverse member and drives the transverse member to move the pusher from the retracted position to the fully extended position and back to the retracted position.
According to another form of the invention, a conveyor system includes a first conveyor section, a second conveyor section, and a third conveyor section which is positioned between the first and second conveyor sections. The second conveyor section is offset from the first conveyor section and is generally parallel to the first conveyor section. The third conveyor section includes a conveying surface having a first portion positioned adjacent the output end of the first conveyor section and a second portion which is positioned adjacent the input end of the second conveyor section. The third conveyor section includes a transfer assembly which is adapted to translate an article conveyed on the conveying surface between the first and second portions of the conveying surface to transfer the article from the first conveyor section to the second conveyor section.
In one aspect, the transfer assembly includes a pusher member and a driver which moves the pusher member across the first portion of the conveying surface. The pusher member straddles the conveying surface and includes downwardly depending portions which are interconnected by a transverse member, which is supported by rails. Preferably, the transverse member is driven by the driver and moves the pusher member between the retracted position to the fully extended position. For example, the driver may include a wheel which engages the transverse member to drive the transverse member. In preferred form, the wheel is driven in a circular path to move the pusher member across the first portion of the conveying surface. In further aspects, the wheel is driven in a circular path with a constant velocity whereby the pusher member moves a first speed over the first portion of the conveying surface to contact the article conveyed on the conveying surface and moves the article across the first portion a second speed which is faster than the first speed whereby the pusher member minimizes the initial impact with the article.
In other aspects, the third conveyor section includes a frame. The conveying surface is rotatably supported in the frame and may comprise, for example, a rotatable belt.
In yet another form of the invention, a conveyor system includes a first conveying section, a second conveyor section, and a third conveyor section which is positioned between the first and second conveyor sections. The first and second conveyor sections are substantially parallel and are offset with respect to each other whereby a first portion of the conveying surface of the third conveyor section aligns with the output end of the first conveyor and a second portion of the conveying surface aligns with the input end of the second conveyor section. The third conveyor section is adapted for transferring articles from the first conveyor section to the second conveyor section with a low impact.
According to yet another form of the invention, a transfer assembly includes a conveying surface and a pusher adapted to move across said conveying surface in a translation direction generally orthogonal to the direction of flow of the conveying surface from a retracted position adjacent said conveying surface to an extended position across said conveying surface for translating across said conveying surface in the translation direction.
In one aspect, the pusher straddles said conveying surface. Preferably, the transfer assembly includes a frame, which supports the conveying surface, with the pusher being movably supported on the frame. For example, the pusher is movably supported on said frame by a pair of rails.
In further aspects, the pusher moves across a first portion of the conveying surface at a first speed and moves across a second portion of the conveying surface to move the article at a second speed, wherein said first speed is slower than said second speed thereby minimizing the impact on the article. For example, transfer assembly may include a driver and driver arm, which is rotated by the driver and with pusher member moved across the conveying surface by the rotating driver arm. Preferably, the driver arm rotates in a circular path and, more preferably, at a generally constant angular velocity.
These and other objects, advantages, purposes, and features of the invention will become more apparent from the study of the following description taken in conjunction with the drawings.